An airplane which has good longitudinal stability should have a minimum tendency to?

A well-designed airplane with good longitudinal stability is primarily focused on maintaining a consistent pitch attitude during flight. This stability ensures that once the aircraft is in a certain pitch position, it will naturally return to that position if disturbed. Good longitudinal stability minimizes the tendency to pitch up or down excessively in response to external forces or pilot inputs.

In the context of stability, "pitch" refers to the up-and-down rotation of the aircraft's nose about its lateral axis. An airplane that does not have good longitudinal stability may respond erratically in pitch, leading to difficulties in maintaining level flight or in executing smooth climbs and descents.

The other types of movements, such as yaw and roll, relate to lateral and directional stability rather than longitudinal stability. While an airplane can certainly be designed to handle these movements as well, the question specifically focuses on longitudinal stability, emphasizing the importance of stability in pitch for overall flight safety and control.